Wurtzite structured GaN has a severe polarization effect in the c (0001) plane, compared to which the polarization effect is small in the semipolar (11–22) plane, and there is no polarization effect in the nonpolar (11–20) plane GaN. To investigate the influence of the polarization effect on the band bending at the heterojunction interface, we fabricated tungsten diselenide (WSe2)/(0001) GaN, WSe2/(11–22) GaN, and WSe2/(11–20) GaN heterojunctions. We measured the heterojunction valence band offsets (VBOs) by x-ray photoelectron spectroscopy. The VBOs of the three WSe2/GaN heterojunctions were measured to be 2.43 ± 0.15, 2.51 ± 0.15, and 2.23 ± 0.15 eV, and the conduction band offsets were calculated to be 1.11 ± 0.15, 1.19 ± 0.15, and 0.91 ± 0.15 eV, showing the type II energy band alignment of the three heterojunctions. The results demonstrate that WSe2/(11–22) GaN-faced heterojunction band bending is the largest. This provides theoretical insights for two-dimensional WSe2 and three-dimensional semipolar (11–22) GaN and nonpolar (11–20) GaN heterojunction device preparation.

中文翻译：

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通过 X 射线光电子能谱测定半极性 (11–22) 和非极性 (11–20) 平面中的 WSe2/GaN 异质结能带偏移

纤锌矿结构的GaN在c(0001)面具有严重的极化效应，相比之下在半极性(11-22)面的极化效应较小，而在非极性(11-20)面的GaN则不存在极化效应。为了研究极化效应对异质结界面能带弯曲的影响，我们制备了二硒化钨（WSe2）/（0001）GaN、WSe2/（11-22）GaN和WSe2/（11-20）GaN异质结。我们通过 X 射线光电子能谱测量了异质结价带偏移 (VBO)。测量三个WSe2/GaN异质结的VBO为2.43±0.15、2.51±0.15和2.23±0.15 eV，计算导带偏移为1.11±0.15、1.19±0.15和0.91±0.15 eV，显示三个异质结的 II 型能带排列。结果表明，WSe2/(11–22) GaN 面异质结能带弯曲最大。这为二维 WSe2 和三维半极性 (11-22) GaN 和非极性 (11-20) GaN 异质结器件的制备提供了理论见解。